Art of utilizing solar radiant energy



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WESTON. ART OF UTILIZING SOLAR RADIANT ENERGY. N0. 389,125.

Patented Sept.'4, 1888.

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NITEI) STATES PATENT Fr es.

EDWARD WESTON, OF NEWARK, NEW- .IERSEY.

ART OF UTlLlZiNG SOLAR RADlANT ENERGY.

SPECIFICATION forming part of Letters Patent No. 389,125, datedSeptember 4, 1888.

Application filed October 17, 1887. Serial No. 252,545. (No model.)

To all whom it may concern.-

Be it known that .I, EDWARD 'WEs'roN, of Newark, Essex county, NewJersey, have invented, a new and useful Improvement in the Art ofUtilizing Solar Radiant Energy, of which the following is aspecification.

I propose to transform radiant energy derived from the sun intoelectrical energy, or through electr'icalenergy into mechanical energy.I may directly employ the electrical energy so obtained, or I mayconvert it into mechanical energy prior to such utilization.

In order to carry my improvement in the aforesaid art into practicaleffect, I concentrate or converge the solar beam npon'any electrogenerative apparatus which depends upon an increase of its temperaturefor the production of an electric current, or, in other words, whichwill yield electrical energy in a proportion to the increase oftemperatures to which it is subjected. A thermoelectric element whereintwo bodies of dissimilar metal are placed side by side united at oneend, and everywhere else insulated from one another, is such an electrogenerative apparatus. When several of ,such elements are joined inseries,s0 that their alternate junctions lie near together and in oneplane, such an arrangement is termeda therinopile. lfonejunction of athermoelectric element or one set of jnnctionsin a thermopile be heatedto a fixed temperature and the other junction or set of junctions bemaintained at a lower temperature, then an electrical current will beset up in acircuit including said dissimilar metal bodies,

the electro-motive force of which current in the thermopile will be thesum of the electro-mo tive forces of the currents produced bythc severalelements and will increase up to a maximum proportionately to theincrease of tem- I expose to the solar rays one set of junctions of athermopilc, thus cause an electrical current in a circui t,includingsaid thcrmopile. Inasmuch, however, as for practical purposes it is notexpedient to construct the face of a thermopile of very'large area, Iconcentrate the solar beam upon the face of the thermopile by any knowndevice for that purpose-such as converging mirror or lensso thatrelatively much higher temperature,

and hence greater energy per unit of surface area, may be obtained. Inorder, further, to produce absorption of both heat and light energy, Icover the face of the thermopile with any absorbent material, such aslamp-black; or I may simply dull such surface, so that its capacity forreflecting light-rays may be d1- minished as far as possible. Theelectrical current thus, obtainedl may accumulate in a storage orsecondary battery; or I may conduct it directly to any form ofcleclromotor wherein the electrical energy of said current is convertedinto mechanical energy.

My aforesaid improvement in the art of converting solar radiant energyinto electrical 1 energy is susceptible of being applied in many modesand by the use of many forms of apparatus. Thus in place of a thermopileI may employ any form of heat-battery or galvanic current in a circuitincluding its elements, but which, when the temperature of theelectrolyte is augmented by the application of extraneous heat, (as bythe solar rays converged upon a transparent vessel contaimngsa d elec'trolyte.) undergoes certain chemical reactions, whereby an electricalcurrent is engendered ll] its cireuit.' So, also, as already stated, Imay employ various means for converging or eoucentratiug the solar raysupon the electrogencrative apparatus.

The mode of carrying my invention into practical effect will from theforegoing be obvious to all skilled in the art; but in addition I willnow describe a particular apparatus by which my improvement canbeapplied the same is capable of being exhibited and performed if ctualexperience. Such apparatus is illustrated in the accompanying elec-:trical diagram, which, it will be understood, does not show exactproportions or details of construction. The combinations embodied insaid apparatus I do not herein claim, was much as the same form thesubject of another application for Letters Patent of the United States,filed by me simultaneously herewith, Serial No. 252,544.

In theaocoiupanying drawings, Figure 1 is a general diagrammatic View ofan apparatus cell which at normal temperature yields no I withbeneficial result, in order to show that embodying my invention. Fig. 2represents -the heat-receiving surface of the thermopile in plan view.

Similar letters of reference indicate like parts.

Referring to said drawings, A represents a thermopile composed of barsB0 of dissimilar metals joined at D and E. V

F is a lens, whereby the solar rays are concentrated or converged uponthe surface formed by the junctions D of said pile. Said surface may becovered witha light-absorbing material, G, as lamp-black, substantiallyas indicated in Fig; 2, where a portion of said covering is representedas broken away,,or be simply dulled or darkened, so as not to reflectlight-rays.

The thermopile A. is connected by wires (1 a in circuit with theelectrodes I J of the secondary cell H, and said electrodes are alsoconnected by wires 1) b with the binding-posts of any form ofeleclroinotor, as K. Inter posed in one of the wires b is an ordinarycircuit-closer, 0, whereby circuit-can be established or broken betweenthe secondary cell H and motor K.

At (1 is an electro magnet having its coil in circuit with one ofthewires a. The armature e of said magnet is polarized. Said armature ispivoted atf, and is connectedto one terminal of the magnet-coil, so thatthe circuit proceeds from the'coil through the armature to a stop,wherewith the armature" makes contactwhen attracted by theelectro-magnet, and thence to the secondary cell H. A spiral spring, h,attached to the pivoted armature, aids in retracting the same from thepole of the magnet.

\Vhen the current proceeds from the thermopile to the secondary cell,the magnet and the polarized armature mutually attract, and the circuitto the secondary cell is maintainedp \Vhen, however, thc'strength of thecurrent in the cell becomes greater than that passing to the cell, thenthe magnet-poles are reversed and magnet and armature mutu ally repel,and circuit between cell and thermopile is broken. In this wayshort-circuit ing of the cell through the thermopile may be prevented.This arrangement of automatic circuit-closer I do not claim. I introduceit here merely as illustrative of known appara tus practically usefulfor the purpose stated.

.energy into electrical energy,

The object of the storage or secondary cell is to accumulate the solarradiant energy in the form of electrical energy, so that, forexample,energy accumulated during hours of sunshine may be utilizedduring night or periods of cloudy weather; or, in other words, said cellhere acts substantially as a reservoir into which electrical energy maybe intermittently delivered, but from which it may be taken'as aconstant supply.

I am 'well. aware that various devices have been contrived for directlyutilizing solar'hcat to produce steam or hot air, or for measuring theintensity of solar radiation; butI am not aware that the utilization ofthe suns heat and light-rays through the conversion of solar radiantenergy into electrical energy or into mechanical energy throughintermediateconversion into electrical energy has hitherto beenaccomplished. t

I do not claim herein the improvement in the art utilizing solar radiantenergy by converting said solar energy. into mechanical energy, whichconsists in converting said solar and then eonverting saidelectrical'energyinto mechanical energy, because I intend to make thatinven tion the subject-matter of another application for Letters Patenthereafter -to-be filed, and of this reservation public notice is herebygiven.

I claim-- f 1. The improvement in the art of utilizing solar radiantenergy, which consists inconverting said solar energy into electricalenergy, and then storing and accumulating said electrical energy,substantially as described.

2. The improvement in the art of utilizing and storing solar radiantenergy through converting said solar energy into accumulated electricalenergy, which consists in concentrating or converging the solar raysup0n,and thereby rendering active to produce an electrical current, anelectro-generative apparatus capable of converting heat-energy intoelectrical energy, and then accumulating said electrical energy in asecondary or storage cell, substantially as described.

EDWARD WESTON. \Vitnesses:

II. A. 'Bnominrnn, E. E. CARY.

